content: /*
   * Copyright 2011-2016 David Karnok
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package ix;
  
  import java.util.*;
  import java.util.Map.Entry;
  
  final class IxExcept<T> extends IxSource<T, T> {
  
      final Iterable<? extends T> other;
  
      IxExcept(Iterable<T> source, Iterable<? extends T> other) {
          super(source);
          this.other = other;
      }
  
      @Override
      public Iterator<T> iterator() {
          return new ExceptIterator<T>(source.iterator(), other.iterator());
      }
  
      static final class ExceptIterator<T> extends IxSourceIterator<T, T> {
          final Iterator<? extends T> other;
  
          final LinkedHashMap<T, Boolean> set;
  
          Iterator<Map.Entry<T, Boolean>> setIterator;
  
          boolean once;
  
          boolean second;
  
          ExceptIterator(Iterator<T> it, Iterator<? extends T> other) {
              super(it);
              this.other = other;
              this.set = new LinkedHashMap<T, Boolean>();
          }
  
          @Override
          protected boolean moveNext() {
              LinkedHashMap<T, Boolean> secondSet = set;
              if (!once) {
                  once = true;
                  while (other.hasNext()) {
                      secondSet.put(other.next(), true);
                  }
              }
  
              for (;;) {
                  if (second) {
                      Iterator<Entry<T, Boolean>> sIt = setIterator;
                      while (sIt.hasNext()) {
                          Entry<T, Boolean> e = sIt.next();
  
                          if (e.getValue()) {
                              value = e.getKey();
                              hasValue = true;
                              return true;
                          }
                      }
                      done = true;
                      return false;
                  } else {
                      Iterator<T> fIt = it;
                      while (fIt.hasNext()) {
                          T v = fIt.next();
  
                          Boolean b = secondSet.get(v);
                          if (b == null) {
                              value = v;
                              hasValue = true;
                              return true;
                          }
                          if (b) {
                              secondSet.put(v, false);
                          }
                      }
                      second = true;
                      setIterator = secondSet.entrySet().iterator();
                  }
              }
          }
      }
  }
  